Apparatus for detecting concentration of powder in spiral conveying tube of bilayer electrode array

Abstract

The invention provides an apparatus for detecting the concentration of powder in the spiral conveying tube of a bilayer electrode array. The apparatus comprises a bilayer electrode array sensor, a data acquisition and control system and an image reconstruction computer, the bilayer electrode array sensor is arranged in a position close to a material outlet outside the spiral conveying tube, and is formed by a special circular tube with a low dielectric constant, the outer wall of the special circular tube is pasted with an electrode array, an electrode array is embedded to the inner wall of the special circular tube, and the two ends of the inner electrode array and the outer electrode array are respectively provided with two annular shielding electrodes. The arrangement mode of bilayer electrodes makes adjacent electrodes be isolated through the special circular tube to replace a spacing between original adjacent electrodes, so isolation is reliable, and arrangement is compact, thereby more or larger electrodes can be arranged by fully utilizing the perimeter of the spiral conveying tube in order to obtain more measurement data for carrying out capacitance chromatography imaging, or the detected capacitance is sensitive and reliable, and the quality and the resolution of a reconstructed image are improved. The circular tube directly sleeves outside the measured pipeline in the measurement process, so the detection is convenient.

Description

technical field [0001] The invention belongs to the technical field of material conveying detection devices, in particular to a powder concentration detection device in a spiral conveying pipe with a double-layer electrode array, which can be applied to industries such as food, chemical industry and agriculture. Background technique [0002] Screw conveying has good controllability and stability for the conveying of powder and granular materials, and is widely used in the transportation, batching and packaging production process of agricultural materials, industrial minerals, chemicals, food processing raw materials and finished products. To realize the quantitative feeding of screw conveying, the concentration of powder is a particularly important determinant, and the detection of powder concentration has always been the difficulty of the screw quantitative feeding measurement and control system. [0003] There are three main methods for powder concentration detection: the ...

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Problems solved by technology

But what it gets is only the local concentration in the pipe section, and it cannot obtain the complete concentration distribution in the pipe section

In 2013, Cui Ziqiang and others applied for a patent for a capacitance tomography sensor with double-layer rotating electrodes (authorized announcement number: CN103454318B), attaching the excitation electrode and the detection electrode to the two rotating tube walls respectively, and can measure the capacitance value from any angle , the main problems and deficiencies are: there are many electrode leads, and continuous rotation is required, resulting in complex structure and poor reliability, and poor applicability to the detection of materials in the pipeline fixedly connected to the device stand; measuring capacitance from any angle, there are measurement times There are many, many useless data, resulting in a large amount of data calculation and processing, complex processing, and poor real-time performance

In 2014, in the patented powder concentration distribution detection device and detection method in the discharge section of the spiral conveying pipe (application publication number: CNIO4316441A), the inventor proposed a detection device for arranging capacitance tomography electrodes in the pipeline, using image reconstruction The powder concentration in the conveying pipe was obtained. Due to the very limited measurement data provided by the 12-electrode electrical capacitance tomography detection device, the reconstruction image provided by the electrical capacitance tomography has a low resolution and low measurement accuracy. At the same time, 12 electrodes Directly arranged on the same cylindrical surface in the pipeline to be tested, it will cause certain damage to the structure of the pipeline during installation, and have a certain impact on the flow field, and it is necessary to process and manufacture a special electrode array for each pipeline to be tested, and the measurement cost is high and the time is long Not enough

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